AP Chemistry – Mr. Montero – Problem Set 1) Convert 10.49 g/ml to lb/in3
2) Hemoglobin (C2952H4664N812O832S8Fe4) is the oxygen carrier in blood. (a) Calculate the molar mass of hemoglobin (b) An average adult has about 5.0 L of blood. Every milliliter of blood has approximately 5.0x109 erythrocytes, or red blood cells, and every red blood cell has about 2.8x108 hemoglobin molecules. Calculate the mass of hemoglobin molecules in grams in an average adult (ans: 7.6x102 g)
3) The density of an acid solution is 1.321 g/cm3. The solution is 29.9% acid by mass (that means there are 29.9 g of acid for every 100 g of solution). What volume of the solution contains 100.0 g of pure acid?
4) The total volume of seawater is 1.5 x 1021 L. Assume that sea water contains 3.1 percent sodium chloride by mass and that its density is 1.03 g/mL. Calculate the total mass of sodium chloride in the ocean in tons (1 ton = 2000 lb; 1 lb = 453.6 g) 5) An aqueous solution of oxalic acid (H2C2O4) is 0.568 M and has a density of 1.022 g/mL. What is the molality of the solution? 6) What is the molarity of a solution prepared by diluting 25.0 mL of 0.400 M potassium hydroxide (KOH) to 2.67 L?
7) What would be the molarity of a solution obtained when 275 mL of 6.00 M sodium hydroxide (NaOH) solution is mixed with each of the following? a) 3.245 L of H2O b) 125 mL of 6.00 M NaOH solution 8) A solution is prepared by dissolving 1.00 g of CuSO4  5 H2O (Copper Sulfate pentahydrate) in enough water to make 10.00 mL of solution. A 1.00 mL portion of this solution is then diluted to a final volume of 10.00 mL. What is the molarity of the final CuSO4 solution? 9) 500 ml of a Sulfuric Acid (H2SO4), is prepared using 100 ml of the Stock Solution. The Stock Solution has a density of 1.84 g/mL and a concentration of 98% (m/m). What is the molarity of the solution? 10)Hematite, Fe2O3, is the most common iron ore. How many moles of hematite are in an ore sample that contains 355 g of iron? Assume hematite is the only source of iron in this ore. 11) What is the molarity of the chloride ion in 250 mL of a solution containing 1.90 g of MgCl2? (The molar mass of MgCl2 is 95.2 g mol‐1 ) 12) For each solution, identify the ions that exist in aqueous solution & specify the concentration of each. a) 0.25 M (NH4)2SO4 b) 0.123 M Na2CO3
13) I. 2 Mn2+ + 4 OH‐ + O2(g)→ 2 MnO2(s) + 2 H2O
II. MnO2(s) + 2 I‐ + 4 H+ → Mn2+ + I2(aq) + 2 H2O III. 2 S2O32‐ + I2(aq) → S4O62‐ + 2 I‐
The reactions above occur in order. The product of the first reaction, MnO2 reacts with iodide to form I2. The iodine reacts with thiosulfate to form S4O62‐. (a) According to the equation above, how many moles of S2O32‐ are required to react with 1.00 mole of O2? (b) If 4.86 milliliters of a 0.0112‐molar Na2S2O3 solution completely reacts in reaction III, what is the number of moles of O2 that reacted? 14) A 1.25‐g sample contains some of the very reactive compound Al(C6H5)3. On treating the compound with aqueous HCl, 0.951 g of C6H6 is obtained. Al(C6H5)3(s) + 3HCl(aq)  AlCl3(aq) + 3C6H6(l) Assuming that Al(C6H5)3 was converted completely to products, what is the weight percent of Al(C6H5)3 in original 1.25‐g sample? 15) In the photographic developing process, silver bromide is dissolved by adding sodium thiosulfate: AgBr(s) + 2 Na2S2O3(aq)  Na3Ag(S2O3)2(aq) + NaBr(aq) If you want to dissolve 0.250 g of AgBr, what volume of 0.0138 M Na2S2O3, in milliliters, should be used? 16) Chlorine is used to disinfect swimming pools. The accepted concentration for this purpose is
1 ppm chlorine, or 1 g of chlorine per million grams of water. Calculate the volume of a chlorine
solution (in milliliters) a home owner should add to her swimming pool if the solution contains
6.0 percent chlorine by mass (6 g of chlorine per 100 g of solution) and there are 2.0 x 104 gallons
of water in the pool. (1 gallon = 3.79 L; density of all liquids = 1.0 g/mL.) (ans = 1.3 x 103 mL.)
17) Tums is a popular remedy for acid indigestion. A typical Tums tablet contains calcium
carbonate plus some inert substances. When ingested, it reacts with the gastric juice (hydrochloric
acid) in the stomach to give off carbon dioxide gas. When a 1.328 g tablet reacted with 40.00 mL
of hydrochloric acid (density = 1.140 g/mL), carbon dioxide gas was given off and the resulting
solution weighed 46.699 g. Calculate the number of liters of carbon dioxide gas released if its
density is 1.81 g/L. (ans = 0.13 L)